Chaining calls without async nodejs

Question

In the codebase i picked up, we have such chains as

funcA(a,b){
 funcB(a, funcC);
}
funcB(a,b,callback){
 callback(a, funcD); // calls funcC
}
funcC(a,b,callback){
 callback(a, funcE); // calls funcD
}

So the functions donT even know what they are calling as callback!..

Needless to say that it s really difficult to read follow this code..

Does it have to be this way? How can I improve this code?

Thanks!

• lukaszfiszer: possible duplicate of Chaining functions with callbacks while keeping separation of concerns
• Orkun: busted :) but i think i ll keep this one.
• Orkun: ... as I think this is a more generic problem. And the answer to the other post might not solve this.

Answer 1

Can the EventEmitter help you with your issue?

http://nodejs.org/api/events.html#events_emitter_on_event_listener

var emitter = require('events').EventEmitter;
function A(a,b) {
 // hard work
 emitter.emit('funcADone', a , b);
}
function B(a,b) {
 var c = a + b;
 emitter.emit('funcBDone', c);
}
function C(c) {
 console.log(c);
}
emitter.on('funcADone', B);
emitter.on('funcBDone', C);
A(1,2);